76 research outputs found
Oral messages improve visual search
Input multimodality combining speech and hand gestures has motivated numerous
usability studies. Contrastingly, issues relating to the design and ergonomic
evaluation of multimodal output messages combining speech with visual
modalities have not yet been addressed extensively. The experimental study
presented here addresses one of these issues. Its aim is to assess the actual
efficiency and usability of oral system messages including brief spatial
information for helping users to locate objects on crowded displays rapidly.
Target presentation mode, scene spatial structure and task difficulty were
chosen as independent variables. Two conditions were defined: the visual target
presentation mode (VP condition) and the multimodal target presentation mode
(MP condition). Each participant carried out two blocks of visual search tasks
(120 tasks per block, and one block per condition). Scene target presentation
mode, scene structure and task difficulty were found to be significant factors.
Multimodal target presentation proved to be more efficient than visual target
presentation. In addition, participants expressed very positive judgments on
multimodal target presentations which were preferred to visual presentations by
a majority of participants. Besides, the contribution of spatial messages to
visual search speed and accuracy was influenced by scene spatial structure and
task difficulty: (i) messages improved search efficiency to a lesser extent for
2D array layouts than for some other symmetrical layouts, although the use of
2D arrays for displaying pictures is currently prevailing; (ii) message
usefulness increased with task difficulty. Most of these results are
statistically significant.Comment: 4 page
How really effective are Multimodal Hints in enhancing Visual Target Spotting? Some evidence from a usability study
The main aim of the work presented here is to contribute to computer science
advances in the multimodal usability area, in-as-much as it addresses one of
the major issues relating to the generation of effective oral system messages:
how to design messages which effectively help users to locate specific
graphical objects in information visualisations? An experimental study was
carried out to determine whether oral messages including coarse information on
the locations of graphical objects on the current display may facilitate target
detection tasks sufficiently for making it worth while to integrate such
messages in GUIs. The display spatial layout varied in order to test the
influence of visual presentation structure on the contribution of these
messages to facilitating visual search on crowded displays. Finally, three
levels of task difficulty were defined, based mainly on the target visual
complexity and the number of distractors in the scene. The findings suggest
that spatial information messages improve participants' visual search
performances significantly; they are more appropriate to radial structures than
to matrix, random and elleptic structures; and, they are particularly useful
for performing difficult visual search tasks.Comment: 9 page
A Comparison of Paper Sketch and Interactive Wireframe by Eye Movements Analysis, Survey, and Interview
Eye movement-based analyses have been extensively performed on graphical user interface designs, mainly on high-fidelity prototypes such as coded prototypes. However, practitioners usually initiate the development life cycle with low-fidelity prototypes, such as mock-ups or sketches. Since little or no eye movement analysis has been performed on the latter, would eye tracking transpose its benefits from high- to low-fidelity prototypes and produce different results? To bridge this gap, we performed an eye movement-based analysis that compares gaze point indexes, gaze event types and durations, fixation, and saccade indexes produced by participants between two treatments, a paper prototype vs. a wireframe. The paper also reports a qualitative analysis based on the answers provided by these participants in a semi-directed interview and on a perceived usability questionnaire with 14 items. Due to its interactivity, the wireframe seems to foster a more exploratory approach to design (e.g., testing and navigating more extensively) than the paper prototype
The Agile UX Development Lifecycle: Combining Formative Usability and Agile Methods
This paper contributes a method variation that helps cross-functional teams combine both formative usability and agile methods to develop interactive systems. Both methods are iterative, continuous and focus on delivering value to users, which makes their combination possible. The âagile UX development lifecycleâ supports and facilitates the synchronization of the steps involved in both formative usability and agile sprints in an operable manner and is intended for design and development settings. We present a case study that illustrates the extent to which this tool meets the needs of real-world cross-functional teams, describing the gains in efficiency it can provide but also guidelines for increasing the benefits gained from this combination in design and development settings
Assistance orale à la recherche visuelle - étude expérimentale de l'apport d'indications spatiales à la détection de cibles
http://www.hcirn.com/res/period/rihm.phpNational audienceThis paper describes an experimental study that aims at assessing the actual contribution of voice system messages to visual search efficiency and comfort. Messages which include spatial information on the target location are meant to support search for familiar targets in collections of photographs (30 per display). 24 participants carried out 240 visual search tasks in two conditions differing from each other in initial target presentation only. The isolated target was presented either simultaneously with an oral message (multimodal presentation, MP), or without any message (visual presentation, VP). Averaged target selection times were thrice longer and errors almost twice more frequent in the VP condition than in the MP condition. In addition, the contribution of spatial messages to visual search rapidity and accuracy was influenced by display layout and task difficulty. Most results are statistically significant. Besides, subjective judgments indicate that oral messages were well accepted
Feature extraction and selection for objective gait analysis and fall risk assessment by accelerometry
<p>Abstract</p> <p>Background</p> <p>Falls in the elderly is nowadays a major concern because of their consequences on elderly general health and moral states. Moreover, the aging of the population and the increasing life expectancy make the prediction of falls more and more important. The analysis presented in this article makes a first step in this direction providing a way to analyze gait and classify hospitalized elderly fallers and non-faller. This tool, based on an accelerometer network and signal processing, gives objective informations about the gait and does not need any special gait laboratory as optical analysis do. The tool is also simple to use by a non expert and can therefore be widely used on a large set of patients.</p> <p>Method</p> <p>A population of 20 hospitalized elderlies was asked to execute several classical clinical tests evaluating their risk of falling. They were also asked if they experienced any fall in the last 12 months. The accelerations of the limbs were recorded during the clinical tests with an accelerometer network distributed on the body. A total of 67 features were extracted from the accelerometric signal recorded during a simple 25 m walking test at comfort speed. A feature selection algorithm was used to select those able to classify subjects at risk and not at risk for several classification algorithms types.</p> <p>Results</p> <p>The results showed that several classification algorithms were able to discriminate people from the two groups of interest: fallers and non-fallers hospitalized elderlies. The classification performances of the used algorithms were compared. Moreover a subset of the 67 features was considered to be significantly different between the two groups using a t-test.</p> <p>Conclusions</p> <p>This study gives a method to classify a population of hospitalized elderlies in two groups: at risk of falling or not at risk based on accelerometric data. This is a first step to design a risk of falling assessment system that could be used to provide the right treatment as soon as possible before the fall and its consequences. This tool could also be used to evaluate the risk several times during the revalidation procedure.</p
Tactile Presentation of Network Data: Text, Matrix or Diagram?
Visualisations are commonly used to understand social, biological and other
kinds of networks. Currently, we do not know how to effectively present network
data to people who are blind or have low-vision (BLV). We ran a controlled
study with 8 BLV participants comparing four tactile representations: organic
node-link diagram, grid node-link diagram, adjacency matrix and braille list.
We found that the node-link representations were preferred and more effective
for path following and cluster identification while the matrix and list were
better for adjacency tasks. This is broadly in line with findings for the
corresponding visual representations.Comment: To appear in the ACM CHI Conference on Human Factors in Computing
Systems (CHI 2020
Assistance multimodale Ă l'exploration de visualisations 2D interactives
This work is about the design of a new form of Human-Computer Interaction : the speech + visual presentation combination as an output multimodality. More precisely, it deals with the valuation of the potential benefits from the speech, as a graphical expression mode, during visual target detection tasks in 2D interactive layouts.We used an experimental approach to show the influence of oral messages, including the spatial localisation of the target in the layout, on users speed and accuracy. We also valued the subjective satisfaction of the users about this assistance to visual exploration. Three experimental studies showed that multimodal presentations of the target facilitate and improve users performances, considering both speed and accuracy. They also showed that visual exploration strategies, without any oral message, depend on the spatial organisation of the information displayed.Ce travail porte sur la conception d'une nouvelle forme d'interaction Homme-Machine : la multimodalité parole+présentation visuelle en sortie du systÚme. Plus précisément, l'étude porte sur l'évaluation des apports potentiels de la parole, en tant que mode d'expression complémentaire du graphique, lors du repérage visuel de cibles au sein d'affichages 2D interactifs. Nous avons adopté une approche expérimentale pour déterminer l'influence d'indications spatiales orales sur la rapidité et la précision du repérage de cibles et évaluer la satisfaction subjective d'utilisateurs potentiels de cette forme d'assistance à l'activité d'exploration visuelle. Les différentes études réalisées ont montré d'une part que les présentations multimodales facilitent et améliorent les performances des utilisateurs pour le repérage visuel, en termes de temps et de précision de sélection des cibles. Elles ont montré d'autre part que les stratégies d'exploration visuelle des affichages, en l'absence de messages sonores, dépendent de l'organisation spatiale des informations au sein de l'affichage graphique
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